The collision, in the westbound direction at the Cutting Boulevard off-ramp, killed 47-year-old Martin Gutierrez, according to the Contra Costa County Coroner's Office.

Gutierrez was one of six people in a 2000 Ford Sport SUV, a vehicle designed to hold only five, and was riding in the hatchback area of the SUV with no seat belt, according to the California Highway Patrol. He was ejected from the vehicle when the driver swerved, lost control, hit another vehicle and rolled over, the CHP said.

The collision was first reported about 8:50 p.m. on Sunday. The driver told CHP officers she was trying to avoid a pothole.

All four lanes of westbound Highway 80 were closed as the CHP investigated the scene and crews cleared the roadway, according to the CHP. The roadway was cleared around 11:30 p.m.

Bay City News Service contributed to this story. Rick Hurd covers public safety. Contact him at 925-945-4782 and follow him at Twitter.com/3rdERH.